Bruce RODRIGUES, Edward S. YASKOWIAK, Brian J. HEARN, and H. Dawn MARSHALL
Correspondence: H. Dawn Marshall, Department of Biology, Memorial University of Newfoundland, St. John’s, NL, A1B 3X9, Canada. Email: email@example.com
Received 7 November 2012 – Accepted 8 January 2013
Inferences about sources and routes of colonization are important to understanding and managing introduced species. The Southern Red-backed Vole (SRBV; Myodes gapperi), not native to Newfoundland, was recently discovered in the western interior of the island, and its range is rapidly expanding. Theories regarding the origin of these animals include migration from an earlier release on a small coastal island, accompaniment of pulpwood imports, or an unsanctioned release as part of Newfoundland Marten (Martes americana atrata) recovery efforts. To determine the source, route, and potential timing of introduction to the island, we analyzed mitochondrial control-region sequences of 155 animals from Newfoundland and the two most likely sources, Cape Breton and Labrador. Although Cape Breton and Labrador contain phylogenetically distinct suites of haplotypes, both regions are part of the “eastern” clade of SRBV, indicating that the northeastern-most part of the range was recolonized from an eastern forest refugial lineage isolated during the Pleistocene. The Newfoundland population of SRBV contained only two haplotypes, one found in 89 individuals from multiple sampling locations that clusters with the Cape Breton subclade, and the other found in three individuals from Mine Pond and five from Labrador. We conclude that there have been at least two introductions to the island, with the Cape Breton-sourced introduction occurring earlier than the Labrador event; low diversity is consistent with recent timing of these events. Success of introduced voles in Newfoundland, despite little genetic diversity, probably reflects an exploitable niche for a broadly adapted boreal small mammal.
Key Words: Myodes gapperi, mitochondrial DNA, phylogeography, invasive species, Newfoundland Marten recovery plan.